package com.htiiot.hbase;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.*;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.IdentityTableMapper;
import org.apache.hadoop.hbase.mapreduce.TableInputFormat;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

import java.io.IOException;

@InterfaceAudience.Public
@InterfaceStability.Stable
public class TsdbUidRefact {
    private static final Log LOG = LogFactory.getLog(TsdbUidRefact.class);
    final static String NAME = "TsdbUidRefact-";
    final static String RAW_SCAN = "hbase.mapreduce.include.deleted.rows";
    final static String EXPORT_BATCHING = "hbase.export.scanner.batch";

    static class GTsdbUidMapper
            extends TableMapper<ImmutableBytesWritable, Result> {

        private static char index = '_';

        @Override
        public void map(ImmutableBytesWritable key, Result value, Context context)
                throws IOException, InterruptedException {
            //if rowkey is dn?
            String rowkey = Bytes.toStringBinary(key.get());
            if (rowkey.length() > 32 && rowkey.charAt(32) == index) {//means rowkey is dn
                String subRowkey = rowkey.substring(0, 32);
                byte[] rowBytes = Bytes.toBytesBinary(subRowkey);
                Cell[] cells = value.rawCells();
                for (int i = 0; i < cells.length; i++) {
                    Cell newCell = CellUtil.createCell(rowBytes, CellUtil.cloneFamily(cells[i]), CellUtil.cloneQualifier(cells[i]), cells[i].getTimestamp(), cells[i].getTypeByte(), CellUtil.cloneValue(cells[i]));
                    cells[i] = newCell;
                }
                context.write(new ImmutableBytesWritable(Bytes.toBytesBinary(subRowkey)), Result.create(cells));
            } else {//this means rowkey is not dn
                if (value.containsColumn("name".getBytes(), "metrics".getBytes())) {//this Result line has name:metrics
                    String nameMetrics = Bytes.toStringBinary(value.getValue("name".getBytes(), "metrics".getBytes()));
                    if (nameMetrics.length() > 32 && index == nameMetrics.charAt(32)) {
                        String subNameMetrics = nameMetrics.substring(0, 32);
                        Cell[] cells = value.rawCells();
                        for (int i = 0; i < cells.length; i++) {
                            if ("name".equals(Bytes.toStringBinary(CellUtil.cloneFamily(cells[i]))) && "metrics".equals(Bytes.toStringBinary(CellUtil.cloneQualifier(cells[i])))) {
                                Cell newCell = CellUtil.createCell(CellUtil.cloneRow(cells[i]), CellUtil.cloneFamily(cells[i]), CellUtil.cloneQualifier(cells[i]), cells[i].getTimestamp(), cells[i].getTypeByte(), Bytes.toBytesBinary(subNameMetrics));
                                cells[i] = newCell;
                                break;
                            }
                        }
                        Result valueRefact = Result.create(cells);
                        context.write(key, valueRefact);
                    } else {
                        context.write(key, value);
                    }
                } else {
                    context.write(key, value);
                }
            }
        }
    }

        public static Job createSubmittableJob(Configuration conf, String[] args)
                throws IOException {
            String tableName = args[0];
            Path outputDir = new Path(args[1]);
            Job job = new Job(conf, NAME+tableName);
            job.setJarByClass(TsdbUidRefact.class);
            // Set optional scan parameters
            Scan s = getConfiguredScanForJob(conf, args);
            IdentityTableMapper.initJob(tableName, s, GTsdbUidMapper.class, job);
            // No reducers.  Just write straight to output files.
            job.setNumReduceTasks(0);
            job.setOutputFormatClass(SequenceFileOutputFormat.class);
            job.setOutputKeyClass(ImmutableBytesWritable.class);
            job.setOutputValueClass(Result.class);
            FileOutputFormat.setOutputPath(job, outputDir); // job conf doesn't contain the conf so doesn't have a default fs.
            return job;
        }

        private static Scan getConfiguredScanForJob(Configuration conf, String[] args) throws IOException {
            Scan s = new Scan();
            // Optional arguments.
            // Set Scan Versions
            int versions = args.length > 2 ? Integer.parseInt(args[2]) : 1;
            s.setMaxVersions(versions);
            // Set Scan Range
            long startTime = args.length > 3 ? Long.parseLong(args[3]) : 0L;
            long endTime = args.length > 4 ? Long.parseLong(args[4]) : Long.MAX_VALUE;
            s.setTimeRange(startTime, endTime);
            // Set cache blocks
            s.setCacheBlocks(false);
            // set Start and Stop row
            if (conf.get(TableInputFormat.SCAN_ROW_START) != null) {
                s.setStartRow(Bytes.toBytes(conf.get(TableInputFormat.SCAN_ROW_START)));
            }
            if (conf.get(TableInputFormat.SCAN_ROW_STOP) != null) {
                s.setStopRow(Bytes.toBytes(conf.get(TableInputFormat.SCAN_ROW_STOP)));
            }
            // Set Scan Column Family
            boolean raw = Boolean.parseBoolean(conf.get(RAW_SCAN));
            if (raw) {
                s.setRaw(raw);
            }

            if (conf.get(TableInputFormat.SCAN_COLUMN_FAMILY) != null) {
                s.addFamily(Bytes.toBytes(conf.get(TableInputFormat.SCAN_COLUMN_FAMILY)));
            }
            // Set RowFilter or Prefix Filter if applicable.
            Filter exportFilter = getExportFilter(args);
            if (exportFilter != null) {
                LOG.info("Setting Scan Filter for Export.");
                s.setFilter(exportFilter);
            }

            int batching = conf.getInt(EXPORT_BATCHING, -1);
            if (batching != -1) {
                try {
                    s.setBatch(batching);
                } catch (IncompatibleFilterException e) {
                    LOG.error("Batching could not be set", e);
                }
            }
            LOG.info("versions=" + versions + ", starttime=" + startTime +
                    ", endtime=" + endTime + ", keepDeletedCells=" + raw);
            return s;
        }

        private static Filter getExportFilter(String[] args) {
            Filter exportFilter = null;
            String filterCriteria = (args.length > 5) ? args[5] : null;
            if (filterCriteria == null) return null;
            if (filterCriteria.startsWith("^")) {
                String regexPattern = filterCriteria.substring(1, filterCriteria.length());
                exportFilter = new RowFilter(CompareOp.EQUAL, new RegexStringComparator(regexPattern));
            } else {
                exportFilter = new PrefixFilter(Bytes.toBytes(filterCriteria));
            }
            return exportFilter;
        }

        /*
         * @param errorMsg Error message.  Can be null.
         */
        private static void usage(final String errorMsg) {
            if (errorMsg != null && errorMsg.length() > 0) {
                System.err.println("ERROR: " + errorMsg);
            }
            System.err.println("Usage: Export [-D <property=value>]* <tablename> <outputdir> [<versions> " +
                    "[<starttime> [<endtime>]] [^[regex pattern] or [Prefix] to filter]]\n");
            System.err.println("  Note: -D properties will be applied to the conf used. ");
            System.err.println("  For example: ");
            System.err.println("   -D mapreduce.output.fileoutputformat.compress=true");
            System.err.println("   -D mapreduce.output.fileoutputformat.compress.codec=org.apache.hadoop.io.compress.GzipCodec");
            System.err.println("   -D mapreduce.output.fileoutputformat.compress.type=BLOCK");
            System.err.println("  Additionally, the following SCAN properties can be specified");
            System.err.println("  to control/limit what is exported..");
            System.err.println("   -D " + TableInputFormat.SCAN_COLUMN_FAMILY + "=<familyName>");
            System.err.println("   -D " + RAW_SCAN + "=true");
            System.err.println("   -D " + TableInputFormat.SCAN_ROW_START + "=<ROWSTART>");
            System.err.println("   -D " + TableInputFormat.SCAN_ROW_STOP + "=<ROWSTOP>");
            System.err.println("For performance consider the following properties:\n"
                    + "   -Dhbase.client.scanner.caching=100\n"
                    + "   -Dmapreduce.map.speculative=false\n"
                    + "   -Dmapreduce.reduce.speculative=false");
            System.err.println("For tables with very wide rows consider setting the batch size as below:\n"
                    + "   -D" + EXPORT_BATCHING + "=10");
        }

        //args[0]表名 args[1]输出路径
        public static void main(String[] args) throws Exception {
            Configuration conf = HBaseConfiguration.create();
            String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
            if (otherArgs.length < 2) {
                usage("Wrong number of arguments: " + otherArgs.length);
                System.exit(-1);
            }
            Job job = createSubmittableJob(conf, otherArgs);
            System.exit(job.waitForCompletion(true) ? 0 : 1);
        }


}